Compressive Behavior Assessment of a Newly Developed Circular Cell-based Lattice Structure

The composites composed of Al-based auxetic lattice structures and silicate rubbers were fabricated by pressure infiltration technology. The compressive behavior and deformation characteristic of the composites were investigated related with the relative densities of the auxetic lattice structures. We found that the composites exhibit a longer plateau region than the non-filled Al-based auxetic lattice structures, and the relative density of the auxetic lattice structures play an important role in the compressive mechanical properties, the higher the relative density, the higher flow stress. It is also noticing that, the composite structures show different deformation and damage mechanism due to the filled incompressible silicate rubber. It is expected that the study may provide useful information for the applications of composite structure.

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Dynamic compressive behavior of a modified additively manufactured rhombic dodecahedron 316L stainless steel lattice structure

Thin-Walled Structures ◽

10.1016/j.tws.2019.106586 ◽

2020 ◽

Vol 148 ◽

pp. 106586 ◽

Cited By ~ 11

Author(s):

Xiaofei Cao ◽

Dengbao Xiao ◽

Ying Li ◽

Weibin Wen ◽

Tian Zhao ◽

...

Keyword(s):

Stainless Steel ◽

316L Stainless Steel ◽

Lattice Structure ◽

Compressive Behavior ◽

Rhombic Dodecahedron

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Structural analysis of the photosynthetic membrane from Ectothiorhodospira halochloris

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010007727x ◽

1983 ◽

Vol 41 ◽

pp. 740-741

Author(s):

H. Engelhardt ◽

R. Guckenberger ◽

W. Baumeister

Keyword(s):

Lattice Structure ◽

Bacterial Species ◽

Hexagonal Lattice ◽

Reaction Centre ◽

Photosynthetic Membrane ◽

Rhodopseudomonas Viridis ◽

Photosynthetic Membranes ◽

Ectothiorhodospira Halochloris ◽

Main Components

Bacterial photosynthetic membranes contain, apart from lipids and electron transport components, reaction centre (RC) and light harvesting (LH) polypeptides as the main components. The RC-LH complexes in Rhodopseudomonas viridis membranes are known since quite seme time to form a hexagonal lattice structure in vivo; hence this membrane attracted the particular attention of electron microscopists. Contrary to previous claims in the literature we found, however, that 2-D periodically organized photosynthetic membranes are not a unique feature of Rhodopseudomonas viridis. At least five bacterial species, all bacteriophyll b - containing, possess membranes with the RC-LH complexes regularly arrayed. All these membranes appear to have a similar lattice structure and fine-morphology. The lattice spacings of the Ectothiorhodospira haloohloris, Ectothiorhodospira abdelmalekii and Rhodopseudomonas viridis membranes are close to 13 nm, those of Thiocapsa pfennigii and Rhodopseudomonas sulfoviridis are slightly smaller (∼12.5 nm).

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Electron-Channelling Patterns: Principles and Techniques

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100091986 ◽

1976 ◽

Vol 34 ◽

pp. 400-401

Author(s):

David C. Joy

Keyword(s):

Crystal Structure ◽

Electron Flux ◽

Lattice Structure ◽

Incident Beam ◽

Bloch Wave ◽

Crystalline Solid ◽

Angle Of Incidence ◽

Electron Channelling ◽

Regular Arrangement ◽

Backscattered Signals

In a crystalline solid the regular arrangement of the lattice structure influences the interaction of the incident beam with the specimen, leading to changes in both the transmitted and backscattered signals when the angle of incidence of the beam to the specimen is changed. For the simplest case the electron flux inside the specimen can be visualized as the sum of two, standing wave distributions of electrons (Fig. 1). Bloch wave 1 is concentrated mainly between the atom rows and so only interacts weakly with them. It is therefore transmitted well and backscattered weakly. Bloch wave 2 is concentrated on the line of atom centers and is therefore transmitted poorly and backscattered strongly. The ratio of the excitation of wave 1 to wave 2 varies with the angle between the incident beam and the crystal structure.

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Microstructural Study of Diamond Deformed Under High Pressure and Temperature

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100118072 ◽

1985 ◽

Vol 43 ◽

pp. 230-231

Author(s):

E. F. Koch

Keyword(s):

High Pressure ◽

High Temperature ◽

Lattice Structure ◽

Diamond Particle ◽

Polycrystalline Diamond ◽

Sintering Process ◽

Ion Milling ◽

Sintered Compact ◽

Transmission Electron ◽

High Pressure Sintering

Because of the extremely rigid lattice structure of diamond, generating new dislocations or moving existing dislocations in diamond by applying mechanical stress at ambient temperature is very difficult. Analysis of portions of diamonds deformed under bending stress at elevated temperature has shown that diamond deforms plastically under suitable conditions and that its primary slip systems are on the ﹛111﹜ planes. Plastic deformation in diamond is more commonly observed during the high temperature - high pressure sintering process used to make diamond compacts. The pressure and temperature conditions in the sintering presses are sufficiently high that many diamond grains in the sintered compact show deformed microtructures.In this report commercially available polycrystalline diamond discs for rock cutting applications were analyzed to study the deformation substructures in the diamond grains using transmission electron microscopy. An individual diamond particle can be plastically deformed in a high pressure apparatus at high temperature, but it is nearly impossible to prepare such a particle for TEM observation, since any medium in which the diamond is mounted wears away faster than the diamond during ion milling and the diamond is lost.

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Structure of stacking faults in pyrite using TEM techniques

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100122198 ◽

1992 ◽

Vol 50 (1) ◽

pp. 358-359

Author(s):

Raja Subramanian ◽

Kenneth S. Vecchio

Keyword(s):

Lattice Structure ◽

Stacking Faults ◽

Covalent Bond ◽

Group Symmetry ◽

Iron Pyrite ◽

Dislocation Glide ◽

Partial Dislocations ◽

Transmission Electron ◽

Contrast Analysis ◽

Chlorine Ions

The structure of stacking faults and partial dislocations in iron pyrite (FeS2) have been studied using transmission electron microscopy. Pyrite has the NaCl structure in which the sodium ions are replaced by iron and chlorine ions by covalently-bonded pairs of sulfur ions. These sulfur pairs are oriented along the <111> direction. This covalent bond between sulfur atoms is the strongest bond in pyrite with Pa3 space group symmetry. These sulfur pairs are believed to move as a whole during dislocation glide. The lattice structure across these stacking faults is of interest as the presence of these stacking faults has been preliminarily linked to a higher sulfur reactivity in pyrite. Conventional TEM contrast analysis and high resolution lattice imaging of the faulted area in the TEM specimen has been carried out.

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Distortion in lattice-resolution scanned-probe microscope images

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100148447 ◽

1993 ◽

Vol 51 ◽

pp. 522-523

Author(s):

L. Fei

Keyword(s):

Film Studies ◽

Lattice Structure ◽

Substrate Material ◽

Repulsive Force ◽

Instrument Calibration ◽

Microscope Images ◽

Probe Microscope ◽

Electron Microscopes ◽

Diffraction Patterns ◽

Lattice Resolution

Scanned probe microscopes (SPM) have been widely used for studying the structure of a variety material surfaces and thin films. Interpretation of SPM images, however, remains a debatable subject at best. Unlike electron microscopes (EMs) where diffraction patterns and images regularly provide data on lattice spacings and angles within 1-2% and ∽1° accuracy, our experience indicates that lattice distances and angles in raw SPM images can be off by as much as 10% and ∽6°, respectively. Because SPM images can be affected by processes like the coupling between fast and slow scan direction, hysteresis of piezoelectric scanner, thermal drift, anisotropic tip and sample interaction, etc., the causes for such a large discrepancy maybe complex even though manufacturers suggest that the correction can be done through only instrument calibration.We show here that scanning repulsive force microscope (SFM or AFM) images of freshly cleaved mica, a substrate material used for thin film studies as well as for SFM instrument calibration, are distorted compared with the lattice structure expected for mica.

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Validity of the Elderly Behavior Assessment for Relatives (EBAR)

European Journal of Psychological Assessment ◽

10.1027//1015-5759.16.1.77 ◽

2000 ◽

Vol 16 (1) ◽

pp. 77-83 ◽

Cited By ~ 1

Author(s):

Lina Pezzuti ◽

Caterina Laicardi ◽

Marco Lauriola

Keyword(s):

Cognitive Functioning ◽

Mini Mental State Examination ◽

Rating Scale ◽

Good Health ◽

The Elderly ◽

Behavior Assessment ◽

Elderly Persons ◽

Behavior Rating Scale ◽

Components Analysis ◽

State Examination

Summary: An Elderly Behavior Assessment for Relatives (EBAR), updating the GERRI ( Schwartz, 1983 ), was administered to relatives (or significant others) of 349 elderly persons, from 60 to over 80 years of age, living at home, in good health and without cognitive impairment. A trained psychologist administered subjects the Life Satisfaction for Elderly Scale (LSES), the Instrumental Activity of Daily Living (IADL), the Mini Mental State Examination (MMSE), and personally answered to an overall elderly behavior rating scale (RA). EBAR items were first examined. The more attractive and less discriminative statements were excluded. A principal components analysis was carried out on the remaining EBAR items. Three factors were extracted. After varimax rotation they were tentatively labeled: Everyday Cognitive Functioning, Depression, and Hostility. Factor-driven EBAR subscales were designed, taking into account simpler items in the factor matrix. Results provide evidence for EBAR construct validity. Everyday Cognitive Functioning is connected to the IADL and the RA scores; Depression is very highly related to the LSES; Hostility is weakly related to RA, IADL, and MMSE, indicating that the scale needs further investigation.

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